WASHINGTON (AP) - Amid new questions about President Bush's drive to topple Saddam Hussein, several House Democrats urged lawmakers on Thursday to conduct an official inquiry to determine whether the president intentionally misled Congress.

At a public forum where the word "impeachment" loomed large, Exhibit A was the so-called Downing Street memo, a prewar document leaked from inside the British government to The Sunday Times of London a month and a half ago. Rep. John Conyers of Michigan, the ranking Democrat on the House Judiciary Committee, organized the event.

Recounting a meeting of Prime Minister Tony Blair's national security team, the memo says the Bush administration believed that war was inevitable and was determined to use intelligence about weapons of mass destruction to justify the ouster of Saddam.

"The intelligence and facts were being fixed around the policy," one of the participants was quoted as saying at the meeting, which took place just after British officials returned from Washington.

The president "may have deliberately deceived the United States to get us into a war," Jerrold Nadler, D-N.Y., said. "Was the president of the United States a fool or a knave?"

The Democratic congressmen were relegated to a tiny room in the bottom of the Capitol and the Republicans who run the House scheduled 11 major votes to coincide with the afternoon event.

"We have not been told the truth," Cindy Sheehan, whose soldier son was killed in Baghdad a year ago, told the Democrats. "If this administration doesn't have anything to hide, they should be down here testifying."

The White House refuses to respond to a May 5 letter from 122 congressional Democrats about whether there was a coordinated effort to "fix" the intelligence and facts around the policy, as the Downing Street memo says.

Conyers and a half-dozen other members of Congress were stopped at the White House gate later Thursday when they hand-delivered petitions signed by 560,000 Americans who want Bush to provide a detailed response to the Downing Street memo. When Conyers couldn't get in, an anti-war demonstrator shouted, "Send Bush out!" Eventually, White House aides retrieved the petitions at the gate and took them into the West Wing.

"Quite frankly, evidence that appears to be building up points to whether or not the president has deliberately misled Congress to make the most important decision a president has to make, going to war," Rep. Charles Rangel of New York, senior Democrat on the House Ways and Means Committee, said earlier at the event on Capitol Hill.

Misleading Congress is an impeachable offense, a point that Rangel underscored by saying he's already been through two impeachments, of President Nixon in Watergate and President Clinton for an affair with a White House intern.

Conyers pointed to statements by Bush in the run-up to invasion that war would be a last resort. "The veracity of those statements has - to put it mildly - come into question," he said.

Former Ambassador Joseph Wilson said, "We are having this discussion today because we failed to have it three years ago when we went to war."

"It used to be said that democracies were difficult to mobilize for war precisely because of the debate required," Wilson said, going on to say the lack of debate in this case allowed the war to happen.

Wilson wrote a 2003 newspaper opinion piece criticizing the Bush administration's claim that Iraq had sought uranium in Niger. After the piece appeared someone in the Bush administration leaked the identity of Wilson's wife as a CIA operative, exposing her cover.

Wilson has said he believes the leak was retaliation for his critical comments. The Justice Department is investigating.

John Bonifaz, a lawyer and co-founder of a new group called AfterDowningStreet.org, said the lack of interest by congressional Republicans in the Downing Street memo is like Congress during Nixon's presidency saying "we don't want" the Watergate tapes.